JP5119019B2 - Method for producing steam reforming catalyst for LPG - Google Patents

Description

The present invention relates to the production how suitable catalysts for use in the steam reforming of liquefied petroleum gas (LPG), in particular provides a method for producing superior LPG for steam reforming catalyst activity in a low temperature range Is.

  Ruthenium-containing catalysts have been widely used for steam reforming of hydrocarbons in recent years because they exhibit excellent catalytic performance such as high activity and excellent carbon deposition resistance even under low steam / carbon ratio operating conditions.

Regarding the ruthenium-containing catalyst, a catalyst in which ruthenium is supported on a zirconia support (Patent Document 1), or zirconia having alumina as a support and zirconia sol as a precursor is supported as a co-catalyst, and ruthenium as an active ingredient. By bringing a catalyst containing the catalyst (Patent Document 2) or a solution containing a ruthenium compound, a zirconium compound and an alkaline earth metal or a rare earth element into contact with the support, the ruthenium component is brought close to the zirconium component on the support. (Patent Document 3) or the like supported in a highly dispersed state is proposed.

  When hydrogen production is carried out by steam reforming of hydrocarbons, particularly liquefied petroleum gas, energy saving and high durability of the production process are desired. With conventional reforming catalysts, it is difficult to obtain a reformed gas with a hydrogen concentration exceeding its equilibrium composition. In order to obtain a reformed gas with a predetermined high concentration of hydrogen, the reformed catalyst is modified in a temperature range exceeding 600 ° C. In addition, the steam / carbon (S / C) ratio needs to be 3.0 or more in order to suppress the carbon deposition that causes the blockage of the system. As a result, it is difficult to save energy by reducing the amount of heat input for reforming. Further, in the hydrogen separation membrane reformer, when the temperature exceeds 600 ° C., there is a problem that the durability of the separation membrane is remarkably lowered.

Focusing on this point, the present invention aims to provide a method for producing a steam reforming catalyst for excellent liquefied petroleum gas to the active in a low temperature region.

In order to achieve the above object, according to the present invention described in claim 1, in the production of a steam reforming catalyst for LPG, 0.5 to 1.0 wt% of ruthenium chloride as an active metal is used as an additive. A mixed solution in which 0.5 to 1.0 wt % of nickel nitrate is dissolved and a suspension in which aerosil alumina serving as a catalyst carrier is suspended are mixed, and the mixture is dried and then granulated. The pulverized and sized particles are characterized in that they are reduced by a hydrogen gas stream in an atmosphere having a temperature equal to or higher than a predetermined temperature.

Here, the aerosil alumina is an aluminum oxide fine particle (fumed alumina) obtained by a gas phase reaction using an aerosil production method that vaporizes silicon chloride and synthesizes silica fine particles by a gas phase reaction in a high temperature hydrogen flame. Means.

The present invention will become active metal ruthenium chloride and 0.5 to 1.0% and the additive to become nickel nitrate 0.5 to 1.0% and the dissolved mixture, fumed alumina as a catalyst carrier The mixture is dried and sized, and subjected to a reduction treatment with hydrogen gas in an atmosphere at a predetermined temperature or higher to obtain a steam reforming catalyst for LPG. The carrier can be supported in a highly dispersed state.

  In the steam reforming catalyst for LPG of the present invention formed by the above-described method, methanation of carbon monoxide and carbon dioxide that occurs as a sequential reaction of steam reforming can be suppressed, and a conventional reforming catalyst is used. A hydrogen concentration higher than the equilibrium composition of steam reforming can be obtained. As a result, reforming can be performed at a lower temperature, the amount of input heat in the reforming process can be reduced, energy can be saved, and hydrogen used in the reformer can be reduced. It is possible to reduce the heat damage to the separation membrane and extend the life of the hydrogen separation membrane.

  In addition, since the steam reforming catalyst for LPG of the present invention formed by the above-described method can be reformed with a smaller S / C ratio than the conventional catalyst, the amount of heat required for vaporization can be reduced. Can save energy.

  Furthermore, in the steam reforming catalyst for LPG of the present invention formed by the above method, the hydrogen concentration can be increased by increasing the space velocity (SV) value. Thereby, reduction of the catalyst amount can also be expected.

FIG. 1 is a flowchart for explaining the procedure of the method for producing a steam reforming catalyst for LPG according to the present invention.
First, the operation of dissolving the two Tsu Kell compound is additive ruthenium compound is active metal ion-exchanged water and (S1), fumed alumina consisting surface area 100 m 2 / ^g approximately powder comprising a carrier After suspending in ion-exchanged water, the operation of boiling once and then cooling to a predetermined temperature (80 ° C.) or so (S2) is performed in parallel.

Then, an ion-exchange water ruthenium compound and two Tsu Kell compound is dissolved once boiling was suspended fumed alumina, mixing the ion exchange water which was cooled (S3), the mixture The solution is evaporated to solidify (S4).

  Next, the solidified product is further heated and dried at a temperature of about 60 ° C. (S5), and the dried product is granulated (S6).

  The sized granule is further subjected to a reduction treatment by flowing hydrogen gas for 2 hours under an atmosphere at a temperature of 550 ° C. or higher (S7) to obtain an LPG steam reforming catalyst.

A solution prepared by dissolving 0.25088 g of ruthenium chloride as a ruthenium compound and 0.55585 g of nickel nitrate as a nickel compound in 50 ml of ion exchange water is prepared. On the other hand, 9.8 g of fumed alumina is suspended in 250 ml of ion-exchanged water and then boiled, and then cooled to about 80 ° C. is prepared.

The ion-exchanged water obtained by dissolving the ruthenium compound and the nickel compound and the fumed alumina are suspended and mixed with the heated-cooled solution. After sufficiently stirring and mixing, the water is evaporated to obtain the ruthenium compound. And nickel compound are dispersed in fumed alumina .

The solidified product obtained by evaporating moisture is dried in a drier set at a temperature of about 60 ° C. for 6 hours, and then sized into granules having a particle size of about 1.4 to 2.0 mm. This sized product is allowed to act for 5 hours with hydrogen gas set at a flow rate of about 40 cc / min in an atmosphere at a temperature of 600 ° C. or higher to obtain a catalyst. The the composition of the catalyst, 1 wt% ruthenium of the active metal, two Tsu Kell has become a contained 1 wt% is additive. It is assumed that ruthenium and nickel are alloyed during the reduction treatment.

FIG. 2 is a test apparatus for a steam reformer.
This test apparatus is comprised of an inner cylinder (2) that houses the reforming catalyst (1) and a heater (3) that heats the inner cylinder (2). The reforming catalyst accommodating portion (6) is formed by supporting the catalyst stopper (4) via the stopper support cylinder (5). In the figure, symbol (7) is quartz wool filled on the inflow side of the reforming catalyst housing (6), symbol (8) is a recondensing device arranged in the outlet gas passage (9), and symbol (10) is the catalyst layer. A temperature detector constituted by a thermocouple for detecting the temperature, reference numeral (11), is a temperature detector for detecting the temperature outside the inner cylinder. The catalyst stopper (4) and the stopper support cylinder (5) are both made of a stainless steel mesh plate.

The steam reforming catalyst prepared by the above-mentioned method is filled in the test apparatus, and propane gas and steam are mixed under the conditions of space velocity: 2,000 / h, pressure: 0.53 MPaG, S / C: 2.8. The concentration of the derived hydrogen gas was measured by changing the temperature through a test apparatus that maintained the temperature. The results are shown in Table 1.
As a comparative example, the concentration of the derived hydrogen gas was measured for a case where granular alumina was used as a carrier and a catalyst containing 5% ruthenium as an active metal was used. Incidentally, the hydrogen gas concentration in an equilibrium state under the same temperature condition was also compared.

  FIG. 3 shows the relationship between the elapsed time and the hydrogen concentration.

  As a result, in the catalyst according to the present invention, it was confirmed that the hydrogen concentration was increased by about 1 to 1.5% in each temperature zone. Incidentally, the carbon monoxide concentration in the derived gas using the catalyst of the present invention showed a value about 1% higher than the carbon monoxide concentration in the equilibrium state. This is probably because the catalyst according to the present invention suppresses the methanation reaction.

As a result, in order to obtain an equivalent hydrogen concentration, the catalyst according to the present invention can reduce the processing temperature. And lowering the treatment temperature can contribute to the reduction of the input heat amount, and the durability of the hydrogen separation membrane can be improved.
Further, in the catalyst according to the present invention, the ruthenium content is about 1/5 as compared with the conventional ruthenium-containing catalyst, so that the amount of expensive ruthenium can be reduced.

  In order to investigate the effect of the space velocity on the hydrogen concentration, the space velocity was changed, and the temperature change was made in a test apparatus that maintained the conditions of processing temperature: 600 ° C., pressure: 0.53 MPaG, S / C: 2.8. The concentration of the derived hydrogen gas was measured. The results are shown in Table 2.

As a result, when a conventional ruthenium-containing steam reforming catalyst is used, the hydrogen concentration is constant regardless of the change in space velocity, whereas in the catalyst according to the present invention, when the space velocity increases, It was confirmed that the hydrogen concentration increased. Thereby, in order to obtain the equivalent hydrogen concentration, the amount of catalyst can be reduced, and the cost required for steam reforming can be reduced.

In the above embodiment, as the composition of the catalyst, ruthenium active metal 1 wt%, although it is additive two Tsu Kell has been described in connection with what is contained 1 wt%, as the mixing ratio of ruthenium 0.5~1.0wt %, If the mixing ratio of the nickel compound is in the range of 0.5 to 1.0 wt%, the above-described effects can be obtained. Further, as the second additive, a lithium compound may be added at an upper limit of about 0.5 wt%.

  The present invention can be used for hydrogen production technology using liquefied petroleum gas as a raw material.

It is a flow explaining the procedure of the steam reforming catalyst manufacturing method for LPG which concerns on this invention. It is a figure which shows the test apparatus of a steam reformer. It is a graph which shows the relationship between hydrogen concentration and elapsed time.

Claims (2)

  A mixed liquid in which 0.5 to 1.0 wt% of ruthenium chloride as an active metal and 0.5 to 1.0 wt% of nickel nitrate as an additive are dissolved, and fumed alumina as a catalyst carrier are suspended. The resulting suspension is mixed, dried, then granulated, and the sized product is reduced by a hydrogen gas stream in a temperature atmosphere above a predetermined temperature. A method for producing a steam reforming catalyst for LPG. An operation of dissolving 0.5 to 1.0 wt% of ruthenium chloride as an active metal and 0.5 to 1.0 wt% of nickel nitrate as an additive in ion- exchanged water to prepare a mixed solution; The fumed alumina is suspended in ion-exchanged water, and the operation of boiling and cooling after the suspension is performed in parallel.
Mixing ion-exchanged water in which an active metal and an additive are dissolved, and ion-exchanged water boiled and cooled after suspending a catalyst carrier made of fumed alumina,
The mixed solution is evaporated and solidified, and the solidified solid is further dried by heating,
This dried product is granulated into granules,
2. The steam reforming catalyst for LPG according to claim 1, wherein the sized granule is further subjected to a reduction treatment by flowing hydrogen gas for 2 hours under an atmosphere of 550 ° C. or higher. Production method.

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